Strain effects and thickness dependence of ferroelectric properties in epitaxial BiFe O3 thin films

Abstract

A "misfit strain-temperature" phase diagram for BiFe O3 thin film was constructed based on the Landau-Devonshire theory with the mechanical substrate effect. It is found that the polarization instabilities result in the formation of the monoclinic phases in BiFe O3 thin films. The effective substrate lattice parameter has been introduced to calculate the film thickness dependence of the polarization and the dielectric constants. The theoretical results are in agreement with the experimental data for the thickness dependence of ferroelectric properties of the BiFe O3 epitaxial thin films on SrTi O3 and Si substrates. © 2008 American Institute of Physics.